Dorr miller



D. MILLER.

STEERiNG GEAR.

APPLICATION man 0m28.191s.

Patented Dec. 30, 1919.

m RJ MM srarns f Donn MILLER, or CHICAGO; ILLINOIS.

STEERING-GEAR.'

Application sied December 2s, 191e. serial No.

To all whom z'mag/ concern:

Be it known that l, Dorm MILLER, a citizen of the United States,residing at Chicago, county of Cook, State of Illinois, have invented acertain new and`useful Improvement in Steering-Gears, and declare thefollowing' to be a full, clear, and exact descriptionof theI same, suchas'will enable others skilled in the art to whichr yit pertains to makeand use the same,reference being had to the accompanying drawings, whichform a part of this specification. 4

My invention has for its object to produce a simple, powerful mechanismwhich will make it-` possible to steer with a minimum expenditure ofeffort and obtain substantially complete locking against backwardimpacts'transmitted from the wheels, whereby a motor carwill becompletely .responsive` to the slightest steering suggestion of thedriver and for all practical purposes wholly unresponsive to tendenciesof `the wheels, because ofthe condition of the road, or for otherreasons, to vary the direction of travel. v

` ,A steering gear having the aforesaid characteristics lends itselfvery advantageously to what is known as quick steering"I and therefore,viewed ,in one of itsaspects, my invention may be said to have foritsgoebjectto produce a simple and efiicient quick The variousIfeaturesof novelty whereby my` invention is characterized willhereinafter be pointed out with .particularity in the claims', but, fora fullunderstanding of my invention and of its objects and advantages,reference may be hadto the following detailed description taken inconnection with the accompanying drawing, wherein: l i

Figure l is a view partly-.inV side elevation and partly in sectionthrough a steerin mechanism arranged inaccordance with a preferred formof my invention; e e

F ig. 2 is a section on a somewhat larger scale taken approximatelyonline 2%-2 of Fig. l, looking in the direction of the arrows, thehousing being omitted and the ends of the rock shaft broken away '5 Fig.3 is a sidev elevation of the driving segment;

Specification of Letters Patent;

Patented Dec. so, 1919. 139,280. l

Fig. `4 is a side elevation ofthe driven member including the rockshaft; and

Fig. 5 is a `side elevation of thestationarycam plate between which andthe segment the driven member is locatedf Referring to the drawing, `lrepresents a steering post at the lower end of which is a suitablecasing or housing, 2, into which extends the lower end of a Steeringshaft, 3. All these parts may take any usual or preferred forms.Extending. transversely through the casing is a rock shaft, 4,- whoseaxis is at right angles to the axis of the steering shaft. Y member 5,

and independent ofthe latter and el' the rock shaft` are disks orplates, the rock shaft. The member 6 is rotatable relatively to thecasing while the `member 7 is fixed to the. casing in any suitablewa'yas, for example, by devices, 8. The disk 5 has two openings,4 9,extending through the saine, these openings being any desired distanceapart. In the arrangement shown, the holes 9 are placed at diametricallyopposed points. The faces of the members 6 and 7 which lie contiguous tothe member 5 are providedV with cam tracks, l0 and l1, which are similarto each other, each rising gradually and at a uniform rate inbothdirections from a low point to a high point or points. The a1igular.distance "fromV the low pointof each cam track to `onecf the highpoints may vary from asmalljangle to an angle of 180 degrees asillustrated; the two high points of each cani track being superposedupon each other ,in the arrangement shown so that each track is inlsubstance an annular undulating4 surface having one high point and onelow point. The cam surfaces are so disposed that what mayv betermed thecenter line of each will be at the samedistance from theaxis ofthe rockshaft a's'the centers of the holes 9 in the `member. Extending throughthe holes 9 are devices, preferably in the forin'ofballs, 12,'as`illustrated, which are required to oscillate with the rock shaft but arefree to move independently of the latter in either. direction' parallelwith the axis of the rock shaft.

The parts are so proportioned thatv when On opposite sides ofJ the.

6 im@ 75; the center of each of which is at the axis ofV a fasteningdevice or they are assembled as shown in Figs. 1 and 2, with the highpoint, 14, of the cam 10 directly opposite the high point 15 on the cam11, the opposed cam surfaces in the vicinity of the'balls will be justfar enough apart to permit each ball to engage with both cam surfaces;while in any other relative angular position of the two members 6 and 7`there will be found two diametrically opposed points which are spacedapart a distance equal to the diameter of the balls.

The result of this construction is that if the member 6 is turned fromthe position indicated in Figs. 1 and 2, whether toward the right ortoward the left, the opposed cam surfaces in the initial position of oneof the balls approach each other so that the only thing it is possiblefor this ball to do is to travel ahead and this it will do at just theproper rate to remain at all times in contact with both cams. As theball travels ahead it moves gradually away from the high point of thecam 11 and toward the low point so that its rate of travel need be onlyhalf what it would be if it engaged with a. plain surface instead ofwith the cam 11 and were pushed ahead along this plain surface by thecam 10. Therefore the ball, which happens to be the driven ball, and themember 5 which must move with it, will be moved about the axis of therock shaft at just half the speed of the member 6. It will be seen thatwhen one of the balls is driven ahead by the cam 10, the other ball iscarried ahead with the member 5 so as always to remain in contact withboth of the cam surfaces and the latter ball is therefore always readyto act as the driving member for the rock shaft upon reversing thedirection of rotation of the member 6. It will thus be seen that in anyrelative angular positions of the members 6 and 7 one of the balls isalways ready to take hold instantly and drive the rock shaft when themember 6 is turned in one direction while the other ball is always readyto act as the driving member for the rock shaft when the member 6 isturned in the other direction. Consequently there is never any back lashor lost motion but, since the member 6 is turned in either direction,the member 5 on the rock shaft begins to move in the same direction butat only one-half the speed. v

TWhile the rock shaft responds instantly to any small turning forceapplied to the driving member 6, because of the small angle of the camsurfaces, any turning force eX- erted directly upon the rock shaft haspractically no effect on the driving member 6 which acts in substancelike a wedge of small angle interposed between' the balls and the sidesof the casing and therefore acts as a lock for the rock shaft instead ofpermitting itself to be driven backward by 'the latter.

Lezama ln order to drive the member 6 from the steering shaft, it isprovided with a gear segment, 16, meshing with a pinion, 17, on thelower end of the steering shaft. From the foregoing description it willbe seen that when the steering wheel is turned in either direction, therock shaft is instantly set in motion. When the steering wheel comes torest the, rock shaft does the same and, furthermore, is locked againstmovement in either direction until the steering wheel is againmanipulated, so that road shocks will not be carried back to thesteering wheel.

TWhile the cams may be made to have point contact with the balls, lprefer to make them in the form of grooves curved on the same radius asthe balls so as to produce a line contact instead of a point contact.

I prefer, also, to place between the driving member 6 and the adjacentwall of the casing a suitable wearing plate, 18, preferably of castiron.

lt will be seen that the present invention embodies the same principleof differentiation as that disclosed in my prior application fordifferential gearing, filed March 11, 1915, Serial No. 13,616, only asingle set of cams and engaging elements being required in the presentinstance because the driven shaft is intended to oseillate, while in myaforesaid application a plurality of sets of cams and cam-engagingdevices are required for the purpose of permitting one set to come inoperation after the other and thus make it possible to secure rotationas distinguished from mere oscillation. In my aforesaid application themember corresponding to the rock shaft in the present case is thedriving member, but the reason that the rock shaft is not an effectivedriving member is that the angle of the cams is made smaller than theangle which would be chosen for a differential gear, and this results insuch a great leverage in favor of the member 6 that enlya 4slight force,which may be regarded as negligible, need be applied to the steeringwheel to hold it against back action due to any tendency of the rockshaft to act as a driving member.

W'hile l have illustrated and described with particnlarity only a singlepreferred form of my invention, l do not desire to be limited to theexact structural details thus illustrated and described; but intend tocover all forms and arrangements which come within the terms employed inthe definitions of my invention constituting the appended claims.

l claim:

1. 1n combination, three members located adjacent to each other andmovable relatively to each other about a common axis, the two outermembers each having a cam surface facing the other cam surface andarranged in the arc of a circle having its center at said axis, eachofsaid surfaces rising gradually from a low point to two high points, twoballs carried by and movable with the intermediate member about saidaxis and movable `relatively to the intermediate member in the directionof said axis, said balls being located between said cam surfaces andbeing spaced apart a distance equal to the distance from the low pointon one of the cam surfaces to one of the high points on the sameV camsurface, and means for actuating one of the outer members.`

2. In combination, a rocking device, two members arranged on oppositesides of said rocking device and one of the members being movable aboutthe pivotal axis of the rocking device, each of said members having onthe face directed toward the other a cam surface rising gradually inopposite directions from a low point, said cam surfaces being similar toeach other and similarly arranged, and two similar separated elementscarried by said rocking device and movable therewith in the direction ofthe length of said cam surfaces and movable relatively to said rockingdevice in directions parallel with said axis, and means for actuatingthe aforesaid movable member.

3. In combination, a rock shaft, two disks surrounding the rock shaftand movable relatively thereto, said disks each having a cam surfacefacing the other cam surface and arranged in the arc of a circle havingits center at the axis of the rock shaft, Veach of said surfaces risinggradually in opposite directions from a low point, a part connected withthe rock shaft lying between said disks, two elements carried by saidpart and each engaging with both of Vsaid cam surfaces, said elementsbeing movable angularly with the rock shaft and being movable relativelyto the rock shaft in directionsparallel to the aforesaid axis, 'andmeans for actuating one of said disks.

4. In combination, a member movable angularly about an axis, said memberhaving a cam surface arranged in the arc of a circle about said axis andrising gradually in opposite directions from a low point relatively to aplane extending at right angles to said axis, a stationary member-spaced apart from the aforesaid member and having thereon a cam surfacesimilar to and facing the aforesaidV cam surface, a device arrangedbetween said members and adapted to be moved angularly about saidaxis,and two cam-engaging elements carried by said device and each engagingboth of said `cam surfaces, said cam-engaging elements being movableabout said axis with said device and being movable relatively to saiddevice in directions parallel with said axis.

5. In a steering shaft extending through said casing, two

ear a casing a rock members arranged within the casing about the rockshaft, one of the members being fixed to the casing andthe other beingmovable angularly about the axis of the rock shaft, each of said membershaving a cam surface facing the other cam surface and arranged in thearc of a circle having its center at said axis, each cam surface risinggradually in opposite directions from a low` point, a device fixed tothe rock shaft and lying between said members, two elements carried byand movable with said device about said axis and movable relatively tosaid device in directions parallel with said axis, a steering shaft, anda driving connection between said steering shaft and the aforesaidrotatable member.

G. In a steering gear, a casing, a rock shaft extending through thecasing, two disks arranged within the casing about said shaft, each ofsaid disks having' a cam sur face facing the other cam surface andarranged in the arc of a circle having its center at the axis of therock shaft, each of said surfaces rising gradually in oppositedirections from a low point, a part extend` ing radially from said shaftbetween said disks, two elements carried by and movable with said partabout said axis and movable relatively to said part in directionsparallel with said axis, one of said disks being fixed to the casing,and means for oscillat-` ing the other disk.

7..In combination, a driving member, thereto, said stationary ing memberbeing a stationary member, journaled adjacent member and drivprovidedwith opposed cam surfaces, a drivfen member suitably journaled andcoupling members carried thereby and interposed between the cam surfacesand said cam surfaces being formed to coact with the coupling memberswhereby motion transmitted by the driving member will effect movement ofthe driven member in either direction and the parts will lock underpressure from the driven member to prevent motion being transmittedthereby to the driving member.

8. In combination, a stationary member, a driving member journaledadjacent thereto, said stationary member and driving member beingprovided with opposed cam surfaces, a driven member suitably journaledand coupling members carried thereby and interposed between the camsurfaces and said cams being formed to coact with the coupling memberswhereby motion transmitted by the driving member will effect themovement of the driven member at one half the speed of the former ineither direction and to effect the locking of the parts Linder pressurefrom the driven member to prevent motion being transmitted from thedriven member to the driving member, substantiallyas describe 9. In asteering gear mechanism, a driv- With-to be operative to lock underpressure ing` member and a driven member and Cou- `from the drivenmember to prevent motion plng means therebetween adapted t0 trzinsbeintransmitted thereby te the driving 10 mit motion from the driving memberto the mem el'. 5 driven member in both directions, said ceu- Intestimony whereof, I sign this specifipling means comprising couplingelements cation. and cam members adapted to co-act there- DORR MILLER.

